package com.lagou.utils;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

/**
 * @Author wsl
 * @Date 2021/8/22 21:47
 * @Project_Name mysql
 */
public class DruidUtils {

    //1.定义成员变量
    public static DataSource dataSource;

    //2.静态代码块
    static {
        try {
            //3.创建属性集对象
            Properties p = new Properties();
            //4.加载配置文件Druid连接池，不能够主动加载配置文件，需要指定文件
            InputStream inputStream = DruidUtils.class.getClassLoader().getResourceAsStream("druid.properties");
            //5.使用 properties对象的 load方法 从字节流中读取配置信息
            p.load(inputStream);
            //6.通过工厂类来获取连接池对象
            dataSource = DruidDataSourceFactory.createDataSource(p);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //7.获取连接的方法
    public static Connection getConnection(){
        try {

            return dataSource.getConnection();

        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }
    //9.获取连接池对象
    public static DataSource getDataSource(){
        return dataSource;
    }

    //8.释放资源
    public static void close(Connection con, Statement statement){
        if (null != con &&  null != statement){
            try {
                statement.close();
                //归还连接
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    //9.释放资源，用于查询
    public static void close(Connection con, Statement statement, ResultSet resultSet){
        if (null != con &&  null != statement && null != resultSet){
            try {
                resultSet.close();
                statement.close();
                //归还连接
                con.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}
